Dual service elevator systems



-May S, 1955 W. F-' EAMES DUL SERVICE ELEVATOR SYSTEMS Filed NOV, 4, 1952 9 Sheets-Sheet l ATTORNEY W. F. 'EAMES DUAL SERVICE ELEVATOR SYSTEMS May 3l, 1955 9 Sheets-Sheet 2 Filed NOV. 4, 1952 yDR mvENToR William F. Eames. Blkf T mI :llllslllalllmwmn ....Wm .N\|.||sl.l...||||l.lll-v11l!imw L@ m.; J J F,\.l|l|.!|l|||i||||b|w w J J F F .Db F Er\..l I I I i I i .2.... lalmv e@ www! @Nilllwmz @an E $4 mi.. D D D D D D VNIII l V uk! l llllqm mw U m... U U U U. U r .liiillilllliliiil .Illmw Mllllllllllllll T @w Nwman M M M M G\1|l|..i.l..|.l||l|..l.|i|.l .I @n @n G H. G x&|.|||||||..s|1l|1|.i|e|l|ll i@ mm .as m.. X X X slllllllllilllilrillill@ ||l|||||l|l|| s van. .Hlw Weill! @m w. .m .7. M s llll I|i|i1|l||||||llln|i|lli||||z|h| .lil/@Illu 7&1 m4 W mhll iiiiiiiiii Il wu@ ATTORNEY A zum May 3l, 1955 w, F, EAMES 2,709,503

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ATTORNEY United States Patent O DUAL SERVICE ELEVATOR SYSTEMS William F. Eames, Westfield, N. J., assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 4, 1952, Serial No. 318,651

45 Claims. (Cl. IS7-29) This invention relates to dual service elevator systems and it has particular relation to an elevator system which automatically selects, in accordance with requirements, one of a plurality of types of elevator service.

Various aspects of the invention are applicable either to an elevator system having a single elevator' car or to a system having multiple elevator cars arranged in a bank. Furthermore, aspects of the invention are applicable to elevator systems wherein attendants are provided in the elevator cars for the purpose of operating the elevator cars or to automatic systems wherein the elevator cars may operate without car attendants. Since the invention is particularly suitable for automatic elevators, it will be described with particular' reference to an automatic elevator system.

Elevator systems may be called on to handle various tratiic patterns. Some of these patterns are discussed in my copending patent application Serial No. 166,620, tiled i une 7, 1950, which has issued as Patent 2,624,425. To illustrate the various traiic patterns which may be encountered, reference may be made to an apartment building having an elevator system intended to serve a plurality of lioors. During a major portion of the day the calls for an elevator system in the up direction and in the down direction may be comparatively balanced. However, immediately before the start or a business day, substantial numbers of apartment house tenants may desire elevator service to the lower terminal oor for the purpose of proceeding to their places of employment. Under these circumstances, the number of prospective passengers desiring down service may exceed substantially those desiring up service.

immediately after the close of the business day tenants may return to the apartment building and request transportation from the lower terminal iloor to the various upper floors of the building. Under these circumstances, the number of calls for up service may exceed substantially the number of calls for down elevator service.

ln accordance with the invention, an elevator system is provided which automatically selects the type of service best suited for various tralhc patterns. lf the changes in the trahie pattern are repetitive at regular intervals, the type of service rendered by the elevator system may be changed at regular intervals in any suitable manner as by means of a time switch. in most cases, however, it will be found that the changes in traic patterns occur at irregular intervals. For this reason, the changes in the type of service rendered by the elevator system preferably are made in response to the traffic demand.

Various combinations of types of elevator service may be employed. In a preferred embodiment of the invention, the elevator system may be arranged to provide either a bidirectional selective collective elevator service or a unidirectional selective collective elevator service. in the former type of service, each elevator car is controlled during an up trip to stop successively at each floor which it approaches for which a call is registered by a passenger within the elevator car or by a prospective passenger located at the tloor being approached. Similarly, during a down trip the elevator car is conditioned to stop successively at each tloor approached by the elevator car for which a call is registered by a pas- Sengcr within the elevator car or by a prospective passenger located at the oor which is being approached by the elevator car. Each of the trips of the elevator car may be a complete trip between the terminal iioors. Alternatively, the system may be so designed that durinc a trip of the elevator car in one direction, such as the up direction, the elevator car stops at the farthest floor for which any call is registered. Thereafter, the elevator car travels in the opposite or down direction toward the lower terminal floor and collects calls during the down trip in the customary manner.

For unidirectional selective collective operation, the elevator system may be so designed that an elevator car does not accept calls from prospective passengers located at the various oors of the building during one direction of travel of the elevator car. Thus, if the elevator car is loaded at the lower terminal licor, it proceeds upwardly but fails to stop in response to any call for up service registered by a prospective passenger at any of the intermediate floors of the building. if desired, the elevator car may stop in response to car calls which are registered by passengers within the elevator car. During the return trip of the elevator car, stops are made in response not only to calls registered by passengers within the elevator cars, but to calls registered by prospective passengers at the lloors approached by the elevator car.

As previously pointed out, the transfer of the elevator system from one type of operation to another type of operation may be in response to a timing device such as a time switch. However, in a preferred embodiment of the invention, the transfer is in accordance with a service demand.

Let it be assumed that the elevator system is arranged to provide as a basic service the bidirectional selective collective operation. In response to a service demand indicating the presence of an unusually large number of passengers desiring service in the down direction, the elevator system may be converted to provide a special service such as the unidirectional selective collective operation.

As a further example, let it be assumed that while the system is arranged to provide the basic service, a pronounced demand for service from the lower terminal floor is received. Under such circumstances, the system may be automatically conditioned to provide a special service expediting the transportation of prospective passengers from the lower terminal oor to the other oors of the building. If desired, the system may be conditioned to ignore all calls for service received from prospective passengers at the other floors of the building. The demand for service from the lower terminal oor may be measured in various ways as by the weight of the passengers on the platform of an elevator car located at the lower terminal floor or by the number of passengers loaded within a predetermined time.

At the time the elevator system is transferred from basic to special service, one or more calls for up service may be registered by prospective passengers at the intermediate lloors of the building. in one embodiment of the invention, these calls are stored until the elevator system has completed its special service assignment. Following such completion (which may require only a short time), the elevator system is restored to basic service and proceeds to answer the previously stored calls.

Alternatively, calls tered by prospective for up service which are regispassengers at the floors of the a-,voaeos building at the time of the transfer 4from basic to special service or calls for up service which thereafter are registered by such passengers are conditioned to stop the elevator car during downtravel thereof. Under suc circumstances, the passengers desiring up service are carried to the lower terminal lloor. the next up trip or" the elevator car, these passengers are delivered to the floors which they desire to reach.

Preferably, prospective passengers are notified of the transfer of the elevator system from one type of service to another type of service. For example, when the elevator system is transierred from basic to special service, a buzzer may be operated to notiry prospective passengers that the system is arranged for special service operation. Preferably, however, a signal is located at each of the floors served by the elevator system to notify prospective passengers of lsuch transfer. For example, each signal may bean illuminated sign. When the sign is not illuminated, the system is arranged for basic service operation. In response to the transfer of the system to special service operation, the signs are illuminated to ini rm prospective passengers that the system is conditioned for special service operation.

Signals may be located at each of the floors for each of the elevator cars. Each of the signals indicates the direction in which each associated elevator car will leave the associated floor after stopping at such floor. These signals may be in the form of down iloor lanterns located at each of the floors from which elevator cars may move in a down direction and up floor lantern from which each of the cars may move in an up direction.

ln accordance with one embodiment of the inventori, the elevator system when arranged for special service operation responds to calls registered by passengers within the elevator cars in one direction only of the travel of the elevator cars. Thus an elevator car may be located at the lower terminal floor and thereafter will proceed without stopping to ythe highest licor for which a lcall is registered and will stop at such floor. During the return of the elevator car, the car stops at all doors for which calls `are registered by passengers within the elevator car or for which calls are registered by prospective passengers located at the various iloors. For some ofthe floors, calls will be registered not only by passengers within the elevator car but by prospective passengers located at such floors. Consequently, one stop at each of these floors serves both classes Iof passengers and materially increases the eiliciency of the elevator system.

't is, therefore, an object of the invention to provide 'an'improve-:l elevator system having automatic transfer between a plurality of types of operation.

lt is a second obiect or" the 'invention to provide an elevator system havingautomatic transfer between a plurality of types of operation, together. with signals Vfor notifying prospective passengers of t. e type of operation for which the elevator system is conditioned.

lt is a third object of the invention vto provide an `ele vater system which is automatically transferred in response to a service demand from bidirectional selective collective operation to unidirectional selective collective operation.

lt is a fourth object of the 'invention to -provide a unidirectional selective collective elevator system conditioned to respond to calls for service in one direction from Vprospective'passengers located Vat floors served by the elevator system during travel of the elevator car in the opposite direction.

It is a fifth object of the invention to provide an elevator system which is automatically transferred from one type of operation lto another type of operation, together with means for storing calls for service which can Vnot be answeredduring the latter type of operation until the system is restored to the first-mentioned type of operation.

, Itis a sixth object ofthe invention to provide a unidirectional selective collective elevator system wher@- with the elevator car B.

x. in calls for floors desired by passengers within an elevator car are answered only while the elevator car is conditioned for operation in a predetermined direction.

lt is a seventh object of the invention to provide a selective collective elevator system wherein common registering means are employed for c'alls registered by passengers within an elevator carand by prospective passengers located at floors served by the elevator car.

, lt is an eighth object of the invention to provide an elevator' system which can be transferred from bidirectional selective collective operation .to vunidirectional selective collective operation and which has signals for indicating the direction of travel of an elevator car from each door at which 'it stops.

Cther objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure l is a schematic view with electrical circuits shown in straight line form` of a portion of an elevator system embodying the invention;

Figs. 2 and 3 are schematic views with electrical circuits shown in straight line form of additional portions of the elevator system illustrated in Fig. l.

Figs. lA, 2A and 3A are key representations of electromagnetic switches and relays employed the circuits of g lgs. 12 and 3. It Figs. 1A, 2A, and 3A are placed in horizontal alignment with Figs. l, 2 and 3, respectively, it will be found that the associated coils and contacts of the relays and switches of the horizontally aligned drawings are substantially in horizontal alignment.

Fig. 4 is a schematic view with electrical circuits shown in straight line form illustrating a modification of the elevator system of Figs. l, 2 and 3.

Fig. 4A is a key representation of relays employed vin the circuits of Fig. 4. lf Figs 4 and 4A are placed in horizontal alignment, it will be found that corresponding coils and contacts of t le two are substantially in horizontal alignment;

Fig. 5 is a schematic View with electrical circuits shown in straight lineforrn illustrating a further modiiication of the elevator system illustrated in Figs. l, 2 and 3; and

Fig. 5A is a hey representation of relays employed in the circuit of Fig. 5. lf Figs. 5 and 5A are placed in horizontal alignment, it will b e found that corresponding coils and contacts of the two ligures are in horizontal alignment.

Because of the complexity of the system, a number of Aconventions have been adopted. Although the invention 'may be incorporated in an elevator system having various 'numbers of elevator cars designed to service variou's floors or'landings of a building, the invention will he described with reference to an elevator system employing two cars for the purpose of servinga building having six `floors or landings. The elevator cars will be designated 'oy the reference characters `A and B.

ninasmuch as similar circuits are provided foreach of the elevator cars, a corresponding component for the elevator car E will be identified by the reference character employed 2for the component associated with the corresponding car A, but preceded by the letter B to indicate that the component under consideration is associated It will be understoodthat the elevatorcar B 'and lall componentsspeciiic thereto may be omittedif a single-ear system'is desired.

Relays and switches are employed which may havea number ot sets of contacts which are substantially simultaneously operated. Each set of contacts is identitied by the reference character employed by the relay 'having the contacts followed by a numeral indicating the specific set of contacts. Thus the reference characters Ul and U3 represent the iirst andthird sets of contacts cf the up switch U'for the elevator car A.

An electromagnetic switch or Vrelay may have make or front contacts. Such contacts are closed when the avoaeoe switch or relay is energized and picked up. The contacts are open when the switch or relay is deenergized and dropped out. In addition, relays and switches may have break or back contacts. Such contacts are closed when a relay or switch is deenergized and dropped out. The contacts are opened when a relay or switch is energized and picked up.

To facilitate the presentation ot' the invention, the following apparatus is listed:

Apparatus for car A:

V--speed relay U-up switch M-running relay D*down switch G-holding relay E-induetor slowdown relay F-inductor stopping relay W-up preference relay X-down preference relay 70T--non-interference relay J-reversing relay DR-door relay T-Car-call stopping relay lCR to GCR-car-call registering relays S-floor call stopping relay U-call-above relay 7S-No-call relay Apparatus common to all cars:

UR to SUR-up floor-call registering relays 2DR to SDR-down oor-call registering relays DC-special-service relay 2BC-basic-service relay.

Figure 1 Figure l shows motor control circuits for the elevator cars A and B. For the elevator car A, the control circuits illustrated in Fig. l include a speed relay V, an up switch U, a car-running relay M, a down switch D, a holding relay G, a slowdown inductor relay E, an inductor stopping relay F, an up preference relay W, a down preference relay X, a non-interference relay 70T and a door relay DR. The control circuits are energized from a direct-current source of electrical energy represented by two buses L1 and L2. (The buses ELI and BLZ may be energized fromA the same source and may be tied to the buses L1 and L2 respectively by conductors LT1 and LT2.)

The elevator car A is connected to a counter-weight 10 by means of one or more ropes 11 which pass over a sheave 12. The sheave 12 is secured to a shaft 13 which is rotated by means of suitable motive means. Although any suitable motive means may be employed, it will be assumed that a variable voltage control is employed to control the energization of a direct-current motor 14 which has its armature 14A secured to the shaft 13. The motor 14 has a eld winding 14F which is permanently connected across the buses L1 and L2.

By inspection of Fig. l, it will be noted that the armature 14A and the armature 15A of a direct-current generator 15, together with a series field winding 15S for the generator are connected in a loop series circuit. The generator also has a field winding ISF which is sep-- arately excited for the purpose of controlling the direction and magnitude of the energization of the motor armature 14A.

Because or the large num-ber of circuits employed in an elevator system, it is common practice to provide an elevator system with a floor selector 16. Such a door selector may include an insulating panel 16P, on which a plurality of rows of contact segments are mounted.

The floor selector includes a brush carriage 16C (illustrated in Fig. l in its lower terminal position) which is moved relative to the contact segments in accordance with motions of the elevator car. Thus the movement or' the brush carriage relative to the contact segments cor responds on a reduced scale to the movement of the elevator car relative to the floors of the building served by such car. The movement of the brush carriage may be effected by a screw 16S which is mounted for rotation on the panel IGP and which is in threaded engagement with the carriage. This screw is coupled through suitable gearing 15G to the shaft 13 for rotation by the shaft.

The brush carriage has a separate brush provided for each of the rows of contact segments. Although only two rows ot' contact segments are illustrated in Fig. l, it will be understood that as many rows are provided as are required for the elevator system. For example, as the elevator car proceeds from the lower terminal oor upwardly, a brush bb on the brush carriage successively engages the contact segments b2 to b6. The numerals in the reference characters b2 to b represent the floors with which the contact segments are associated. For example, as the elevator car approaches the second l'ioor, the brush bb engages the contact segment b2 to prepare circuits which are completed it the elevator car is to stop at the second floor in response to a call registered by a passenger within the elevator car.

As a further example, the brush cc on the brush carriage successively engages the contact segments c2 to c6 which are associated respectively with the second to sixth floors. Thus as the elevator car stops at the second floor in response to a car call, the brush cc engages the contact c2 to complete a cancelling or resetting circuit for the purpose of resetting the car call registered for the second floor.

The shaft 13 also carries a brake drum 17. This brake drum cooperates with a spring-applied electro magnetically-released brake of conventional construction. Thus in Fig. l, a brake shoe 17S is biased against the drum 17 in braking position by means of a spring (not shown). The shoe has secured thereto a magnetic arma ture 17M which is associated with a releasing coil or brake coil 17B. When the brake coil 17B is energized by closure of either of the sets of make contacts U1 or D1, the brake shoe 17S is retracted against the bias of the spring to release the brake drum 17 and permit rotation of the shaft 13.

Returning to the generator eld winding 15P, it will be noted that this lield winding is connected across the buses L1 and L2 through a reversing circuit. For example, when the make contacts U2 and U3 are closed, the rield winding 15'F is connected across the buses with proper polarity for up travel of the elevator car. When the make contacts D2 and D3 are closed, the held winding 15P is connected across the buses with proper polarity for down travel of the elevator car. The energization of the field winding 15P may be effected through the resistor R1 when the resistor is not shunted by the make contacts V1 of the speed relay.

The elevator car A contains a plurality of push buttons 1c to 6c for the purpose of registering calls by passengers in the elevator' car respectively for the rst to sixth oors of the building served by the elevator car. In addition, the elevator car has mounted thereon two inductor relays E and F. These inductor relays may be of conventional construction and are employed respectively for controlling the slowdown and stopping of the elevator car. The

inductor slowdown relay E is employed for operating break contacts E1 and E2. This relay has a normally incomplete magnetic circuit. Consequently, energization of the coil of the relay alone is insuieient to operate the contacts. lf the elevator car during down travel appreaches a floor at which it is to stop, the coil of the slowdown relay E is energized and as the car continues its approach, the inductor relay reaches an inductor plate DEP for such door. The inductor plate completes a magnetic circuit for the relay which results in opening of the break contacts E2. It will be understood that a aroasos similar inductor plate is provided for each of the floors at which the elevator car A is to stop during down travel. The opening ofthe contacts E2 initiates a slowdown operation of the elevator car.

lf the elevator car A is to stop at a lloor during up travel, the coil of the relay E is again energized and when the relay reaches the inductor plate UE? associated with the lloor, a magnetic circuit is completed tor the relay which results in opening of the break contacts El. The opening of such contacts initiates a slowdown operation of the elevator car. A similar inductor plate is provided for each of the floors at which the elevator car is to stop during up travel thereof. lt will be understood that the inductor plates are mounted in the hoistway at positions selected to provide suitable slowdown distances for the elevator car.

The inductor stopping relay E cooperates in a similar' manner with inductor plates DFP and UFP. One of the inductor plates DFF is provided for each of the ioors at which the elevator car is to stop for down travel thereof. One of the inductor plates UFP is provided for each of the floors at which the elevator car A is to stop during up travel thereof. Operation of the break contacts F1 and F2 of the stopping relay F initiates a stopping operation of the elevator car. lt will be understood that the inductor plates DFP and UFP are positioned in the hoistway at suitable points to stop the elevator car accurately at each of the associated floors.

The speed relay V is connected across the buses Ll and L2 through either of two parallel arms. One of these arms includes make contacts U5. of the up switch U, a limit switch 19 and the break contacts El of the inductor slowdown relay E. The limit switch l? is of conventional construction. it is normally closed and is opened as the elevator car nears its upper limit of travel.

The second arm for the speed relay V includes in series the make contacts De of the down switch D, a limit switch 20 and the break contacts E2 of the inductor slowdown relay E. The limit switch Ztl is a normally closed cam-operated switch which is opened as the elevator car nears its lower limit of travel.

For the running relay M to be energized, the make contacts DRI of the door relay DR must be closed to indicate that all of the doors associated with the elevator car A are closed. Initial energization or the running relay M also requires closure of the break contacts MT1 of the non-interference relay 76T to indicate that the elevator car has remained at its last stop for a sufficient period to permit discharge or entry of passengers, and closure of the break contacts 7g-1 of a rio-call relay to indicate that a call for elevator service has been registered which the elevator car A can answer.

The energization of the running relay lvl initially is completed through either of two parallel paths. One oi these paths include in series make contacts Wl of the up preference relayl W, break contacts Fl of the inductor stopping relay F, normally closed contacts of a limit switch 21, and the coil of the up switch U. The limit switch is a cam-operated switch which is opened as the elevator car A nears its upper limit of travel. When the running relay M is energized through the lirst path, make contacts U5 close to complete a holding circuit around the contacts 70T?. and Wl.

Fthe second path for initially completing t e energize.- tOn of the running relay lvl includes in series the contacts Xl of the down preference relay X, the break contacts F2 of the inductor stopping relay F, normally closed contacts of a cam-operated limit switch 22 and the coil of the down switch D. The l switch 22 is opened as the elevator car nears its lower limit of travel. m

Energization of the holding relay G and of the inductor relays E and El require closure of the make contacts Ml to indicate that the car is ruiming. in addition, initial energization of these relays requires closure of one of three sets of contacts. Closure of make contacts Tl indicates that the elevator car is to stop at the next iioor in response to a registered car call. Closure of make contacts il indicates that the elevator car during up travel is to stop and reverse at the next floor which is the farthest floor for which a call is registered. Finally, closure of make contacts Sl indicates that the elevator car A is to stop at the next floor reached by the elevator car in response to a floor call which is registered by a prospective passenger for such floor. When the holding relay G is energized, it closes its make contacts G1 to establish a holding circuit around the contacts Tl, .ll and Sl.

For the up preference relay W to be energized, break contacts De and X2 must be closed. ln addition, contacts of a normally closed limit switch 2li must be closed. The limit switch 24 is cam operated to open as the elevator car A nears the upper terminal floor. lt should be noted that the up preference relay W during an up trip of the elevator car remains energized as long as the limit st-vitc i 24 and the break contacts J2 of the reversing relay l are closed. lf the contacts l2 open during such trip before the limit switch opens, the up preference relay W remains energized as long as the make contacts M2 remain closed.

For the down preference relay X to be energized, the break contacts U6 and W2 must be closed and a mechanical limit switch 25 must be closed. The limit switch 25 is normally closed and is cam operated to open as the elevator car A nears its lower terminal door.

The non-interference relay 70T is energized through the make contacts M3 aslong as the elevator car is running. When the contacts M3 open during the stopping of an elevator car at a iloor, the relay 73T remains picked up for a predetermined time sufficient to permit entry or discharge of passengers relative to the elevator car. The dropout time of the relay may be determined in any suitable way and is represented by a resistor R2 which is connected across the relay coil.

For the reversing relay l to be energized, the break contacts X3 must be closed to indicate that the elevator car is conditioned for up travel. Also break contacts 78-2 of the 11o-call relay 73 must be closed to indicate that a. call is registered which can be answered by the elevator car A. The initial energization of Vthe relay is effected through make contacts 'hU as the elevator car A approaches the farthest iloor in the up direction for which a call is registered. When energized, the relay I closes its holding contacts J3 for the purpose of establishing a holding circuit around the contacts 78U1. Make contacts G2 of the holding relay G may shunt the contacts 'iS-2.

The door relay DR is a conventional relay which is connected across the buses for energization through door contacts. Each of the hoistway doors for the elevator car A and the car doors have contacts connected in series with the door relay 'DR to permit energization of the door relay only when all of the doorsv are closed and in safe condition.

Floor stations are provided at the doors ot` the building at which prospective passengers may register calls for service. Thus for the second floor a pushbutton 2U may be operated to register an up floor call. A similar pushbutton is provided for each oor from which an up call may be registered. A pushbutton ZD may be operated at the second iloor to register a down door call. A similar pushbutton may be located at each 'loor from which down service may be desired. These pushbuttons are common to all cars.

Figura 2 The upper part of Pig. 2 illustrates circuits for registering calls for floors desired by passengers within the elevator car. Registration of' a call for'suchV a passenger is effected by operation of one of the car call push buttons 1c to 6c. For example, when the push button 2c is operated, the car-call registering relay ZCR is connected across the buses L1 and L2. This relay closes its malte contacts 2CR1 to establish a holding circuit around the push button 2c. It will be understood that each of the push buttons is biased towards contact open position. Each of the push buttons is similarly associated with one of the car-call registering relays ICR to 6CR, respectively.

The car-call registering circuits have associated therewith four rows of contact segments which are located on the floor selector i6 (Fig. l). The rows of contact segments b2 to b6 and c2 to c6 previously were mentioned. In addition, a row of contact segments a1 to a5 are successively engaged by a brush aa during travel of the elevator car and cooperate with circuits for initiatingY stops of the elevator car during up travel. A row of contact segments Z1 to d5 coact with a brush dd for the purpose of cancelling registered car calls which are answered during up travel of the elevator car.

It is believed that the car-call stopping circuits can be understood best by a presentation of representative operations. If the elevator car A is to stop at the second floor during up travel thereof, the relay ZCR is energized and the contacts ZCRl are closed. As the car approaches the second oor, the brush bb engages the contact segment b2 to complete the following circuit:

L1, ZCRl, b2, bb, W3, DCZ, T, M4, L2

The energization of the car-call stopping relay T results in stopping of the elevator car A at the second floor.

As the elevator car nears the second floor, the brush dd engages the contact segment d2 to complete the following circuit:

L1, ZCRl, ZCRN, d2, dd, Wal, D04, M5, L2

The coil ECRN is a cancelling coil which is wound on the same core with the coil ZCR but which is energized in opposition thereto. Consequently, the energization of the cancelling coil 2CRN results in neutralizing of the coil ZCR and resetting of the registering relay. As the elevator car comes to a stop, the brush bb preferably passes slightly beyond the contact segments b2.

Let it be assumed next that the car call for the second floor is registered during down travel of the elevator car. As the elevator car nears the second floor, the brush aa engages the contact segment a2 to complete the following circuit:

L1, ZCRL a2, an, X4, T, M4, L2

The energization of the car-call stopping relay T results in stopping of the elevator car A at the second floor.

As the elevator car A continues to approach the second floor, the brush cc engages the contact segment c2 to complete the following circuit:

L1, ZCRL CRN, c2, cc, X5, M5, L2

The energization of the cancelling coil ZCRN cancels the call at the second oor. As the elevator car comes to a stop, the brush aa preferably passes slightly beyond the contact segment a2.

The car-call registering circuits for the second to the fifth floors are all similar and will be understood from the discussion of the circuits associated with the second floor. Because of this similarity, car-call registering circuits are illustrated in Fig. 2 only for the second and fifth floors.

The car-call registering circuits for the sixth or upper terminal floor may be similar to those for the second floor. However, since the elevator car can not stop at the upper terminal floor during down travel thereof, it follows that contact segments in the a and a rows are not required for thev upper terminal floor and are not shown for such floor in Fig. 2.

The car-call registering circuits for the first or lower terminal floor may be similar to those discussed for the second floor. However, the elevator car can not stop at the lower terminal floor during up travel thereof. For this reason, contact segments in the b and c rows, are not required for the lower terminal floor and are not illustrated for such floor in Fig. 2.

The break contacts DC2 and DCA', when opened, prevent response by the elevator car to registered car calls during up travel thereof. These contacts are open during special service operation of the system. The contacts may be shunted respectively by switches 29 and 30.

The central part of Fig. 2 illustrates up floor call registering circuits for the elevator system. The push buttons 1U to SU are located respectively at the first to fifth floors and may be operated by prospective passengers desirous of transportation to higher oors. These push buttons are associated respectively with up oor-call registering relays 1UP` to SUR and the relays have cancelling coils IURN to SURN associated therewith. These registering circuits cooperate with two rows e2 to e5 and f1 to f5 of contact segments located on the floor selector 16 of Fig. l. The association of the various components may be understood best by consideration of certain operations. lf a prospective passenger located at the second floor desires transportation in the up direction, he presses the push button 2U to energize through the normally-open switch of the push button and the break contacts DC7, the up floor call registering relay ZUR for the second floor. This relay closes its make contacts 2UR1 to establish a holding circuit around the contacts DC7 and the push button 2U. By inspection, it will be noted that the contacts ZURI now connect the segment e2 for the elevator car A and similar segments such as the segments Bei for the remainder of the elevator cars to the bus L1.

As the elevator car A while traveling in the up direction nears the second floor, the brush ee of the oor selector engages the contact segment e2 to complete the following circuit:

L1, ZURI, e2, ee, W5, DC10, S, L2

The energized floor stop call relay S initiates a stopping operation of the elevator car A at the second oor.

Upon continued motion of the elevator car A toward the second oor, the brush engages the contact segment f2 to complete the following cancelling circuit:

The resultant energization of the cancelling coil ZURN resets the registering relay ZUR. lt should be noted that had the elevator car B answered the call at the second floor, the brush Bee would have engaged the contact segment BeZ to initiate a stopping operation of the car B. Furthermore, as the elevator car B neared the second floor, the brush Bf would have reached the contact segment BfZ to reset the registering relay ZUR.

As the elevator car A comes to a stop at the second Hoor, the brush ee preferably passes slightly beyond the contact segment e2. Preferably, the brush fj remains in engagement with the contact segment f2.

The up floor call registering circuits for each of the intermediate floors are similar to those discussed for the second floor. For this reason, such circuits are illustrated in Fig. 2 only for the second and fifth oors. The circuits may be traced readily by reference to the drawings and to the preceding discussion.

lnasmuch as the elevator car A during up travel always stops at the upper terminal oor, a single contact segment e6 is connected permanently to the bus L1. Consequently, as the elevator car A approaches the sixth floor the brush ee engages the contact segment e5 to stop the elevator car at the sixth oor.

The up floor call registering circuit for the first or lower terminal floor may be similar to those discussed for the second floor. However, inasmuch as the elevator car A always stops at the rst floor during down travel thereof, a contact segment in the e row is not required for the rst floor and none is illustrated in Fig. 2.

The lower portion of Pig. 2 shows circuits for registering down floor calls. Such calls are registered by operation of push buttons 2l) to 6D to close normally-open push button switches which are located respectively at the second to sixth floors for operation by prospective passengers located at these iloors. These push buttons are associated with two rows of contact segments located on each of the door selectors. For example, the elevator car A has associated therewith two rows of contact segments gt to g5 and h2 to h6 which cooperate respectively with brushes gg and lill.

Let it be assumed that a prospective passenger at the second iioor presses the push button 2D for the purpose of registering a down hoor call. Such operation of the push button connects the down door call registering relay 2DR across the buses Ll and L2; The relay closes its malte contacts to establish a holding circuit around the push button 2D. At the sarne time, the contacts EDR connect the contact segment g2 and Bg to the bus Lft.

As the elevator car A approaches the second oor while traveling in the down direction, the brush gg en gages the contact segment g2. to establish the following circuit:

anni, g2, gg, Xs, sa, s, Lz

ln response to the energization of the floor-call stopping relay S, the elevator car is stopped at the second floor. The purpose of the switch 34 will be pointed out below.

As the elevator car A reaches the second oor, the brush :'zlz engages the contact segment h2 to complete the following circuit:

Ll, ZDRl, 2DR? h2, hlt, X7, G3, L2

The eziergization of the cancelling coil EDEN results in resetting of the down floor-call registering relay 2DR. As the elevator car A stops at the second floor, the brush preferably passes slightly beyond the contact segment g2. Howevenvthe brush [ik preferably remains in engagement with the contact segment h2 as long as the elevator car A remains at the second lloor.

Circuits similar to those discussed for the second hoor are associated with each of the push buttons 3D to 5D for the intermediate loors of the building and may be traced readily in Fig, 2. inasmuch as the elevator car can not stop at the upper terminal oor during down travel, a single contact segment gl is connected permanently to the bus L1.

The circuit associated with the push button 6D for the upper terminal floor may be similar to those discussed for the second floor. However, since the elevator car can not stop at the upper terminal oor during down travel, a contact segment in the g row is not required for the sixth hoor.

The make contacts DCM of the special service relay T C are closed when the elevator system is conditioned for special service operation* Closure of the contacts DCll is employed for notifying prospective passengers at the intermediate oors that the system is conditioned for special service operation. ln the embodiment of Fig. 2, a plurality of illuminated signs ZDO to SDO are connected in series with the make contacts DCll across the buses L1 and L2. One of these signs is located at each of the intermediate tloors. When the signs are extinguished, the elevator system is conditioned for basic service operation. When the signs are illuminated, the system is conditioned for special service operation.

Figure 3 The upper part of Fig. 3 illustrates iloor signals the elevator system. These signals are employed the purpose of informing prospective passengers at various oors of the direct-ion in which each elevator ca which stops at the door will leave such oor. Although various types of signals may be employed, it will be assumed that up floor lanterns 1UL to SUL are employed for informing prospective passengers at the rst to iifth iioors, respectively, when the elevator car A is conditioned to leave one of the tloors at which it is stopped in the up direction. ln an analogous manner, down iloor lanterns ZDL to DL are located respectively at the second to sixth iloors for the purpose of informing prospective passengers at these floors when an elevator car stopped at one of these lloors will leave the lloor in a down direction.

The up floor lanterns lUL to 5UL are associated respectively with contact segments jl to ,i5 located in a row on the iloor selector. As the elevator car A proceeds trom the lower terminal door to the upper terminal loor, the Contact segments jl to i5 are engaged successively by brush jj. As the elevator car during up travely approaches a lloor, such as the second floor, the brush ,ij engages the contact segment for such iioor (in the assumed case Contact segment i2). Since the elevator car is assumed to be traveling up, the make contacts W7 of the up preference relay are closed. lf the elevator car stops at the second floor, the break contacts M close to complete a circuit for the oor lantern ZUL across the buses Ll and L2. The illuminated rloor lantern advises a prospective passenger at the second door that the elevator car A will proceed upwardly from the second floor. During up travel of the elevator car, the brush jj thus selects the appropriate iloor lantern to indicate at each door at which the elevator car A stops while conditioned for up travel that the elevator car will leave the floor in the up direction.

The down floor lanterns FDL to 6DL for the second to sixth iloors are associated respectively with contact segments k2 to k6 which are located in a row on the oor selector. As the elevator car A proceeds in a down direction from the up terminal oor to the lower terminal floor, the brush zlz engages successively the contact segments k6 to k2. it the elevator car A is conditioned for down travel, the make contacts X8 of the down preference relay are closed. Consequently, as the down traveling car approaches a oor such as the second tloor at which it is to stop, the brush kk engages the Contact segment k2.. As the elevator car stops at the selected lioor (in this case the second door), the break contacts M6 close to complete an energizing circuit for the door lantern 2DL. This notities prospective passengers at the second iloor that the elevator car will leave the second floor in the down direction.

Inasmuch as the direction preference relays W and X always determine the direction of travel of the elevator car A, it follows that the proper oor lantern always is selected to indicate the direction in which the elevator car A will leave the floor at which it is stopped.

The central part of Fig. 3 illustrates call-above circuits for the elevator cars. Thus the elevator car A has a callabove circuit 36 which includes in series break contacts of all of the call registering relays for floors above the lower terminal floor. The call-above circuit is associated with contact segments ml to m5 which are located in a row on the iloor selector. The call-above circuit controls the energization of a call-above relay 78U which is connected through make contacts W8 between a brush mm which cooperates with the contact segments and the bus L2.

By inspection of Fig. 3, it will be noted that the break contacts ot the registering relays are connected between the bus .L1 and the contact segment ml as follows:

Each of the contact segment ml to m5 is connected to the call-above circuit at a point such that contacts for the registering relays requiring travel of the elevator car above the floor represented by any contact segment are all located above such contact segment. Thus the contact segment m is connected to the callabove circuit between the break contacts 5UR2 and SDRZ. rifhe Contact segment m4 is connected to the callabove circuit between the break contacts EURZ and 4DR2. The remaining connections are clear from Fig. 3. The brush mm engages and leaves each of the contact segments during up car travel in advance of the associated floor.

By inspection of Fig. 3, it will be observed that as long as a call is registered requiring traveling of the elevator car to a iloor above the position of the elevator car A, the call-above relay 78U can not be energized through the callabove circuit.

When the special service relay DC is operated to place the system on special service operation, it may be desirable to modify the call-above circuit. Such modification of the call-above circuit is effected by make contacts D012, DCM, DC and DCIS which shunt the break contacts in Fig. 3 for the call-above circuit 36 which are associated with up oor call registering relays.

A circuit connects the no-call relay 7S between the contact segment ml and the bus L2 through the break contacts IURZ and lCRZ. if no call which may be served by the elevator car A is registered the relay 73 is energized and picked up. As long as such a call is registered, the relay is deenergized and dropped out.

The special service relay DC is energized from the buses Ll and L2 through a resistor R3 and through a plurality of parallel arms each associated with one of the intermediate iloors of the building. Thus one of the arms contains in series make contacts 2DR/l of the down iloor call registering relay for the second floor and a resistor 2R. Another arm contains make contacts 3DR4 of the down floor call registering relay for the third floor and a resistor 3R. Further arms contain make contacts dDRd, 5DR4 and 6DR4 of the down floor call registering relays for the fourth, fifth and sixth floors and resistors 4R, 5R and 6R respectively.

The resistors are proportioned so that current ilowing through a predetermined number of the resistors is required to pick up the relay DC. For present purposes, it will be assumed that currents flowing through at least two of the resistors 2R to 6R are required in order to pick up the special service rleay DC. When it picks up, the relay DC closes make contacts DCZ) to establish with the break contacts ZBC a self-holding circuit.

The basic service relay ZEC determines the return of the elevator system to basic service operation. This relay is connected in series with break contacts ZDRS to DRS of down oor call registering relays for the floors of the building across the buses L1 and L2. Consequently, as long as no down iloor call is registered for a :door of the building, the relay ZEC is energized and picked up.

OperatioftFigm-es l, 2 am] 3 in order to facilitate an understanding of the elevator system, some typical operations of the system now will be considered. It will be assumed first that the elevator car A is located at the lirst floor and that it is conditioned for up travel (up preference relay W is energized). it will be assumed further that an up iioor call is registered at the second lioor by operation of the push button 2U (Fig. 2). As a result of its energization, the up oor call registering relay ZUR closes its make contacts ZURl to establish a self-holding circuit. inasmuch as the elevator car A is at the rst floor, the brush mm (Fig. 3) engages contact segment mit associated with the callabove circuit 36. The energizataion of the up floor-call registering relay for the second fioor opens break contacts ZURZ in the call-above circuit to decnergize the call-above relay '-BU and the no-call relay '78.

The up Hoor-call registering relay also opens its break contacts ZUR3 in the call-above circuit for the car B. However, the present discussion will be confined to the operation of the elevator car A.

Referring to Fig. l, it will bc noted that the deenergized call-above relay 7SU maintains its contacts '73U1 open to prevent energization therethrough of the reversing relay I. The no-cali relay 78 closes its break contacts 7'8--1 to permit energization therethrough of the car-running relay M and one of the switches U or D. Contacts 7S-2 close to permit energization therethrough of the reversing relay.

It will be assumed that the elevator car A has remained at the lower terminal floor for a time sutcient to permit the non-interference relay 7T to time out and close its break contacts 7Tl. lt will be assumed further that the doors associated with the elevator car A are all closed and that the door relay DR is energized to close its make contacts DRI. The doors may be of any conventional type. For example, they may be manually opened and spring closed or they may he power operated in both directions, if desired.

Since the contacts T1 and DRI are closed, the following circuit is established:

Ll., MTL 73:l, W1, Fl, 2l, U, M, DRl, L2

The energized up switch U closes its make contacts U1 to energize the brake coil 17B for the purpose of releasing the elevator brake. Contacts U2 and U3 close to connect the generator held winding 15P for energization with proper polarity for up travel of the elevator car. Contacts U4 close to complete an energizing circuit for the speed relay V and this relay closes to make contacts V1 shunt the resistor Rl. rThe elevator car now accelerates in the up direction.

Closure of the make contacts U5 establishes a holding circuit for the relays U and M around the contacts 7)T1 and Wl. Opening of the break contacts U6 has no immediate etfect on the system operation.

The energization of the running relay M results in closure of the contacts M1 to prepare the relays G, E and F for subsequent operation. Closure of make contacts M2 and M4 and opening of break contacts MS have no immediate effect on the operation of the system.

Closure of make contacts M3 energizes the non-interference relay 70T which opens its contacts 70T1. Because of the holding circuit established through the contacts U5, opening of the contacts 70T1 has no immediate effect on the operation.

Referring to Fig. 3, it will be noted that while the elevator car was stopped at the rst iloor, the up floor lantern IUL was energized through the circuit L1, IUL, jl, fj, W7, M6, L2

to indicate that the elevator car would leave the first floor in the up direction. The energization of the running relay results in opening of the break contacts M6 to extinguish the oor lantern as the elevator car A leaves the rst oor.

As the elevator car approaches the second floor, the brush ee engages the contact segment e2 to complete the following circuit (Fig. 2)

L1, 2UR1, e2, ee, W5, DC10, S, L2

The energized floor call stopping relay S closes its make contacts S1 (Fig. l) to complete an energizing circuit for the relays G, E and F. Energization of the holding relay G results in closure of the make contacts Gi to establish a holding circuit around the contacts S1.

In response to continued movement of the elevator car A toward the second iioor, the inductor slowdown relay E. is horizontally aligned with the slowdown inductor plate UEP for the second oor to complete a magnetic circuit which results in opening of the break contacts E1. Such opening deenergizes the speed relay V which opens its make contacts V1 to insert the resistor R1. in series with the generator field winding 15P. As a result of the decreased energization o the eld Winding, the elevator car A slows to a landing speed.

Continued movement of the elevator car A towards the second floor brings the inductor stopping relay F into horizontal alignment with inductor stopping plate UFP for the second licor. The resultant completion of the magnetic circuit for the relay results in opening of the break contacts F1 to deenergize the up switch U and the running relay M.

The up switch U now opens its make contacts Ul to deenergize the brake coil l'B. The brake shoe 17S now is biased against the drum ll?. In addition, the make contacts U2 and U3 open to deenergize the generator field winding 15P and the elevator car A stops accurately at the second floor. Opening of the make contacts' U4- and U5 and closure of the break Contact U6 have no immediate elect on the operation of the system.

The running relay M when deenergized opens its make contacts Ml to deenergize the relays E, G and F. As the car stops the inductor relays may pass slightly beyond their cooperating inductor plates. The holding relay G opens its self-holding contacts Gl. Opening of` the make contacts M2 and Md and closure of the break contacts M5 have no immediate effect on the operation of the system.

The make contacts M3 in opening deenergize the noninterference relay 79T and this relay starts to time out. Until the relaf,I times out, the contacts itlTl remain open to prevent further starting of the elevator car.

ln approaching the second floor, the elevator car A causes the brush ,ij to engage the Contact segment J2 (Fig. 3) associated with the up floor lantern 2UL. Consequently, as the elevator car stops the break contacts M6 of the running relay close to complete through the contacts W7, the brush jj and the contact segment jZ, an energizing circuit for the up tloor lantern. This informs a prospective passenger at the second door that the elevator car will leave the second licor in the up direction.

Referring next to Fig. 2, it will be noted that asV the elevator car A stops at the second door, the brush ff engages the contact segment f2. Since the holding relay G is energized as the elevator car A approaches the second door, the make contacts G3 are closed to complete the following cancelling circuit:

L1, EURL BURN, f2, ff, W6, G3, L2

'Ehe energization of the cancelling coil ZURN neutralizes the coil of the relay ZUR and resets the relay.

Next it will be assumed that the call for the second oor was registered by a passenger in the elevator car A While the elevator car A is4 located at the lower terminal floor instead of a prospective passenger located at the second floor. The registration of the car call would be etected by operation of the push button 2c to complete an energizing circuit for the call registering relay ECR. The relay ECR closes its make contacts QCR to establish a self-holding circuit. In addition, the break contacts ZCRZ open (Pig. 3) to deenergize the call-above relay 'iSU and the no-call relay 73.

The elevator car A starts in the manner previously described. As it approaches the second door, the brush bb engages the contact segment b2 (Fig. 2) to complete the following circuit:

Ll, ZCRl, b2, bb, Jl/3, DCZ, T, M4, L2

By reference to Fig. l, it will be observed that the energized car-call stopping relay closes its make contacts T1 to complete with the closedy contacts Ml an energizing circuit for the relays G, E and F. These relays cooperate in the manner previously described to, stop the elevator car at the second tloor. During the stopa lo ping operation, the crush da' (Fig. 2) engages the contact segment d2 to complete the following cancelling circuit:

L, ZCRl, ZCRN, d2, dd, W4, DCi, M5, L2

The energization of the cancelling coil ZCRN resets the relay ZCR.

the call for the second floor is the only call registered in the system, the engagement of the brush mm (F1. 3) with the contact segment m2 as the elevator car A approaches the second tloor would result n1 energization of the call-above relay '78D' before the call is cancelled. When energized, the relay ISU closes its make contacts Ul (Fig. l) to energize the reversing relay l. rhis relay closes its make contacts Lier et', since the make contacts Si or Tl were closed, osure oi the contacts il is unnecessary in this particur sequence to stop the elevator car at the second floor.

i y M also open to deenergize the up preference relay M The c' n rgized relay W opens its make contacts Wl, y), We", We, W7 and WS and closes its break The closure of the break contacts W2 comoletes energizing circuit for the down preference X and this relay closes its make contacts Xl, X4, Y' X7, X7 and X8 and opens its break contacts X2 and XE. Consequently, the'elevator car A new is conditioned for down travel. Dropout of the relay G may delayed slightly' to maintain the relay l' energized and the contacts f2 open for a time suicient to assure the above change in direction preference.

By reference to Fig. 3, it will be noted that as the up preference relay is deenergized and the down preference relay is energized, the make contacts W7 open and the make contacts XS close. Consequently, while the elevator car A is at the second door, the down lantern ZDL is illuminated to indicate that 'the elevator car A will leave the second door in the down direction.

For the next example, it will be assumed that elevator car A is located at the lower terminal iloor, an up oor call is r gistered for the third floor and down iloor calls are registered tor the fourth and fth floors. The up iloor call for the third fic-or is registered in the manner discussed for the registration of the up door call for the second door. By reference to Fig. 3, it will be noted that the registration of the up oc-r call for the third door results in opening of the break contacts SUR?. in the call-above circuit 3o to deenergize the call-above relay .U and the no-call relay Till. Similar contacts SURE are open in the call-above circuit B35 for the car B. The relay U opens its make contacts 'SUl (Fig. l) to prevent energization therethrough of the reversing relay l. Contacts m' l and 7S-2 close.

Referring to Fig. 2, it will be observed that the registration ot the down floor call for the fourth oor 1s effected by pressing the push button Lil) which energizes the down floor call registering relay 4DR. This relay closes its self-holding contacts Dit in addition, the break contacts D and DRB (Fig. 3) in the callabove circuits 3e and B35 are also opened. lt will be noted further that the down floor call registering relay closes its make contacts iDli and opens its break contacts DB5 Closing of the contacts Dlfl partially energizes special sevice relay DC but suc-h energizan alone is insufficient to pick up the relay. Deenergizatien or the basic service relay 2SC results in c lor of the break contacts ZBCl to prepare the holding 17 circuit for the special service relay DC for subsequent operation.

Referring again to Fig. 2, the down door call for the fifth door was registered by operation of the push button D to energize the down door call registering relay SDR. This relay closes its self-holding contacts SDRl. In addition, the relay opens its back contacts SDRZ and 5DR3 (Fig. 3) in the call-above circuits 36 and B36. The relay 5DR additionally closes its make contacts 5DR4 and opens its break contacts SDRS. The opening of t-he contacts SDR has no immediate eiect on the operation of the system. However, the closure of the make contacts SDR@ energizes the special service relay DC through the resistor SR. The special service relay DC now is energized through the two resistors 4R and 5R. Under the assumed conditions such energization is sufficient to pick up the special service relay DC. The relay closes its make contacts DC20, to complete with the contacts ZBCI', a self-holding circuit. The relay DC also closes its make contacts DC12 to DC19 to shunt all contacts ot the up floor-call registering relays in the call-above circuits 35 and B36.

As shown in Fig. 2, the 4energization of the special service relay results in opening oi the break contacts DCl, DCE, DCS and DC@ for the purpose of preventing the elevator cars A and B from answering registered car calls during up travel of the elevator cars. However, for present purposes, it will be assumed that the switches 29, B29, 3i) and B30 are closed to shunt these contacts. Consequently, the elevator cars A and B still are conditioned to answer registered car calls during up travel.

The special service relay DC also operates contacts for the purpose of storing registered up door calls and for the purpose of connecting the up floor call push buttons in parallel with the down floor call push buttons. For example, the break contacts DCS open to disconnect the up floor-call registering relay SUR from the push button 5U. if a call is registered by the relay EUR at the time the contacts DCS open, such call will continue to be registered or stored.

in addition, the make contacts DCrS close to connect the push button 5U in parallel with the push button 5D, Consequently, operation of either of the push buttons 5U or 5D results in energization of the down floor call registering relay dDR to register a down oor call.

Contacts of the special service relay similarly are associated with the up door call push buttons for each of the intermediate oors. As a further example, the break contacts DCL open to disconnect the push button 2U from the up floor call-registering relay ZUR. Make contacts DCi close to connect the push button 2U in parallel with the push button 2D for the purpose of energizing by operation of either of the push buttons the down oor call registering relay 2DR.

Since the elevator cars do not stop during up travel at the lower terminal floor, contacts of the special service relay need not be associated with the up floor call push button tU for the rst floor.

The special service relay opens its break contacts DC9 and DCltl to prevent the elevator cars during up travel from answering registered up floor calls. Contacts DC11 close to connect the signs 2DO to SDO in series across the buses Ll and L2. These signs inform prospective passengers at the various floors that the elevator system is conditioned for special service operation and that the elevator cars answer oor calls only while the elevator cars are conditioned for travel in the down direction.

The elevator car A now starts in the up direction from the lower terminal oor in the manner previously described. As the elevator car A approaches the third ioor, the brush ee (Fig. 2) engages the contact segment in the e row for the third door. However, since the break contacts DC are open, the floor-call stopping relay S can 18 not be energized and the elevator car A passes the third iloor without stopping thereat.

The motion of the elevator car A brings the brush mm (Fig. 3) into engagement with the contact segment m4 of the call-above circuit 36. However, since the break contacts SDRZ are open and are located in the circuit above the contact segment m4, the callabove relay '725D can not be energized at this time.

Next the brush mm engages the contact segment m5 to complete the following circuit:

The energized relay '78U closes its make contacts f'SUl. (Fig. 1) to complete an energizing circuit for the reversing relay J. This relay, in turn, closes its make contacts l1 to energize the relays G, E and F. rThe relays G, E and F cooperate to stop the elevator car A at the iitth floor in a manner which will be clear from the foregoing discussion covering the stopping of the elevator car at the second oor.

The reversing relay l also opens its break Contact J2. As the elevator stops, the contacts M2 open to deenergize the up preference relay W. As a result of its deenergization, the relay W closes its break contacts W2 to complete an energizing circuit for the down preference relay X. This conditions the elevator car for down travel. it should be noted that the elevator car is stopping during up travel at a floor in response to a registered down oor call which is the farthest down iloor call in the up direction.

As a result of its stop at the fth iioor, the elevator car A operates circuits which result in resetting or" the down floor-call registering relay for the ifth door. This resetting circuit may be traced in Fig. 2, as follows:

L1, SDR, SDRN, h5, hh, X7, G3, L2

The contacts G3 may have a slight delay in dropout to permit closure of the contacts X7 prior to opening of the contacts G3.

As a result of the resetting operation, the down lioorcall registering relay SDR opens its self-holding contacts SDRI. In addition, the contacts SDR?. and 5DR3 in the call-above circuits (Fig. 3) reclose. Make contacts 5DR4 open but have no immediate etiect on the operation of the system. Contacts SDRS reclose but have no immediate eiect on system operation.

By reference to Fig. 3, it will be understood that as the elevator car A stops at the iith floor, the make contacts W7 open and the make contacts X8 close to energize the down iioor lantern DL. Consequently, this lantern properly indicates the next direction of travel of the elevator car.

After a time sucient to permit dropout of the noninterference relay T (Fig. l) and after the doors associated with the elevator car A are closed, the following circuit is established:

L1, 70T1, 78-1, X1, F2, 22, D, M, DRL L2 The energized down switch D closes its make contacts D1 to energize the brake coil for the purpose of releasing the brake. Contacts D2 and D3 close to energize the field winding ISF with proper polarity for down travel of the elevator car. Contacts D4 energize to energize the speed relay V. This relay closes its make contacts V1 to shunt the resistor R1. The elevator car now accelerates in the down direction.

Closure of the make contacts D5 establishes a holding circuit around the contacts 70T1, I3-l and X1. Opening of the break contacts D6 has no immediate eitect on the operation of the system.

The car running relay M operates in the manner previously described.

As the elevator car A proceeds downwardly, the brush 2'1 The circuits associatedV with the floor-call registering relays may be identical with those illustrated in Fig. 2, with the exception of the following changes. ln Fig. 4, the energization of each of the up floor-call registering relays and the associated cancelling coil for the intermediate oors can be eiiected only through break contacts of the special service relay DC. For example, energization of the up floor-call registering relay SUR and of the associated cancelling coil SURN can be effected only through the break contacts DCS. Consequently, opening of the break contacts DCS must result in resetting of any call registered by the call registering relay SUR and must prevent further registration of a call by such relay. It will be assumed that each of the up floor call push buttons for the intermediate oors is connected in parallel to its associated down iioor call push button through make contacts' of the special service relay which close slightly before theV opening of the break contacts of the special service relay associated with the same push buttons. For example, the make contacts DC6 close slightly before the break contacts DCS open to transfer any call registered by the up floor call registering relay SUR to the down floor call registering relay SDR slightly before the contacts DCS open to reset the relay. Thereafter operation of the push button U operates to register a down oor call by energization of the down oor call registering relay SDR. The break contacts DC'I and the make contacts DCS are associated in a similar manner with the push button 2U.

The switches 34 and B34 of Fig. 2 are not illustrated in Fig. 4. Finally, break contacts M7 operated by the running relay are employed in place of the make contacts G3 (Fig. 2) associated with the holding relay. ri`he contacts M7 close as the elevator car stops to complete a cancelling circuit for any tioor-call registering relay in response to which the elevator car A stops. lf desired the make contacts G3 of relay G can be connected in parallel with contacts M7 to prevent registration of a call at the iioor where the elevator is stopped from the time of start of slowdown until the car is actually leaving the iioor.

Figure 5 As previously explained, the efficiency oi' the elevator' system during unidirectional selective collective operation is materially increased by designing the system to answer calls for service only while elevator cars are conditioned for down travel. This not only results in an improvement in eiiiciency but it permits a substantial simplication of circuits and a reduction in the number or" circuit components required. Such reduction is illustrated in Fig. 5 for the elevator car A. Inasmuch as the elevator car is assumed to provide only unidirectional selective collective operation, contacts of the special service relay DC are not shown.

Car call registering relays lCR to 6CR and their cancelling coils lCRN to 6CRN are employed. Since these relays and their associated circuits are similar, only four registering relays ICR, ZCR, SCR and GCR together with their cancelling coils lCRN, ZCRN, SCRN and CRN are illustrated in the upper part of Fig. 5. These relays and coils are connected in the manner illustrated in Fig. 2 with the following exceptions. lnasmuch as the elevator system does not respond to car calls during up travel thereof, the b and d rows of contact segments are not required and are not illustrated in Fig. 5. This permits elimination of the brushes bb and dd together with the contacts W3 and W4. Contact segment c1 has been added in the c row for engagement by the brush cc as the elevator car reaches the first oor during down travel to energize the cancelling coil lCRN if a call is registered by the call registering relay CR.

In addition, floor call push buttons are connected in parallel with the car call push buttons for the pur'- posc of energizing the same registering relays. Thus the licor call push buttons 2D to 6D are connected in parallel respectively with the car call push buttons 2c to 6c. Consequently, operation of any of the push buttons 2D to 6D register a call for service by energization of one of the registering relays 2CR to 6CR which is answered while the elevator car A is conditioned for down travel. The door call push button 1U is connected in parallel with the car call push button le. Although this floor call push button 1U is answered during down travel of the elevator car, its operation indicates the desire of a prospective passenger to travel in an up direction. For this reason, it is labeled as an up floor push button. Since the call registering circuits shown in the upper part of Fig. 5 replace all of the call registering circuits associated with the car A in Fig. 2, and circuits is eliected.

The call registering circuits illustrated in Fig. 5 also permit a substantial simplification of the call-above circuit. Thus a call-above circuit 36' is illustrated in Fig. 5 which corresponds to the circuit illustrated in Fig. 3. However, the break contacts of all up floorcall registering relays and the break contacts ot all down lioor registering relays illustrated for the callabove circuit of Fig. 3 are omitted from the call-above circuit illustrated in Fig. 5. lt will be understood that an elevator car controlled by the call-above circuit 35 of Fig. 5 will proceed in the up direction directly to the farthest fioor for which a call is registered and will stop at such tioor. The elevator car A then reverses and returns to the lower terminal floor answering all registered calls for service during such return.

Although the invention has been described with reference to certain speciiic embodiments thereof, numerous inodiiications falling within the scope of the invention are possible.

I claim as my invention:

l. An elevator system comprising a structure having a pair or" terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement in two directions relative to the structure to serve the landings, and motive means for moving the elevator car relative to the structure, in combination wtih control means operable in cooperation with the motive means to move the elevator car relative to the structure and to stop the elevator car at predetermined landings, said control means comprising first control means operable for moving and stopping only said one elevator car to provide a first predetermined service for all of said intermediate landings, and auxiliary control means responsive to a predetermined service demand for modifying the moving and stopping of the elevator car to provide a second predetermined service for all of said intermediate landings.

2. An elevator system comprising a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement in two directions relative to the structure to serve the landings, and motive means for moving the elevator car relative to the structure, in combination with control means operable in cooperation with the motive means to move the elevator car relative to the structure and to stop the elevator car at predetermined landings, said control means comprising iirst control means operable for moving and stopping only said one elevator car to provide a substantially balanced service in the two directions of travel of the elevator car for all of said intermediate landings, and second control means responsive to a predetermined service demand for modifying the moving and stopping of the elevator car to provide a service for all of said intermediate landings which is substantially unbalanced in the two directions of travel of the elevator car.

it is clear that a substantial saving in components 

